TM 1-1510-224-10
a. Turbine Gas Temperature Indicators. The
two TGT gages on the instrument panel are calibrated in
degrees Celsius (fig. 2-18). Each gage is connected to
thermocouple probes located in the hot gases between
the turbine wheels. The gages indicate the temperature
present between the compressor turbine and a power
turbine for the corresponding engine.
b. Engine Torquemeters. The two torquemeters
on the instrument panel indicate torque applied to the
propeller shaft of the respective engine (fig. 2-18). Each
gage shows torque in percent of maximum using two
percent graduations and is actuated by an electrical
signal from a torque transmitter mounted on the
reduction
gearbox
which
senses
engine
internal
torquemeter pressure. The torquemeters are protected
by individual 0.5-ampere circuit breakers, placarded
TORQUE METER #1 or #2, on the overhead circuit
breaker panel (fig. 2-9).
c. Turbine Tachometers. The two tachometers
on the instrument panel indicate compressor turbine
RPM (N1) for the respective engine (fig. 2-18). These
indicators register turbine RPM as a percentage of
maximum gas generator RPM. Each instrument is
slaved to a tachometer generator attached to the
respective engine.
d. Oil Pressure/Oil Temperature Indicators. The
two gages on the instrument panel indicate oil pressure
in PSI and oil temperature in °C (fig. 2-18). Oil pressure
is taken from the delivery side of the main oil pressure
pump. Warning annunciators, placarded #1 OIL PRESS
and #2 OIL PRESS, are located in the warning
annunciator panel. Oil temperature is transmitted by a
thermal sensor unit which senses the temperature of the
oil as it leaves the delivery side of the oil pressure pump.
Each gage is connected to pressure and temperature
transmitters installed on the respective engine. Both
instruments are protected by 5-ampere circuit breakers,
placarded OIL PRESS and OIL TEMP #1 or #2, on the
overhead circuit breaker panel (fig. 2-9).
e. Fuel Flow Indicators. Two gages on the
instrument panel (fig. 2-18) indicate the rate of flow for
consumed fuel as measured by sensing units coupled
into the fuel supply lines of the respective engines. The
fuel flow indicators are calibrated in increments of
hundreds of pounds per hour. Both circuits are
protected by 5-ampere circuit breakers, placarded FUEL
FLOW #1 or #2, on the overhead circuit breaker panel
(fig. 2-9).
Section IV. FUEL SYSTEM
2-32. FUEL SUPPLY SYSTEM.
The engine fuel supply system (fig. 2-19)
consists of two identical systems sharing a common fuel
management panel (fig. 2-20) and fuel crossfeed
plumbing (fig. 2-21). Each main fuel system consists of
five interconnected wing tanks and a nacelle tank. Each
auxiliary fuel system consists of one tank located
between the nacelle and the fuselage. A fuel transfer
pump is located within each auxiliary tank. Additionally,
the system has an engine-driven boost pump, a standby
fuel pump located within each nacelle tank, a fuel heater
(engine oil-to-fuel heat exchanger unit), a tank vent
system, a tank vent heating system, and interconnecting
wiring and plumbing. Total fuel tank capacity is shown in
table 2-2. Gravity feed fuel flow is shown in figure 2-22.
a. Engine-Driven Boost Pumps.
CAUTION
Engine
operation
using
only
the
engine-driven primary (high pressure)
fuel pump without standby pump or
engine-driven
boost
pump
fuel
pressure is limited to 10 cumulative
hours. This condition is indicated by
illumination of either the #1 or #2
FUEL PRESS warning annunciator and
the simultaneous illumination of both
MASTER WARNING annunciators. All
time in this category shall be entered
on DA Form 2408-13-1 for the attention
of maintenance personnel.
A gear-driven boost pump mounted on each
engine supplies fuel under pressure to the inlet of the
engine-driven primary high-pressure pump for engine
starting and all normal operations. Either the engine-
driven boost pump or electric standby pump is capable
of supplying sufficient pressure to the engine-driven
primary high-pressure pump and thus maintaining
normal engine operation.
2-42
